The UK Health Security Agency findings add to emerging evidence that Omicron produces milder illness than other variants — but also spreads faster and better evades vaccines.
In South Africa, virus watchers are tentatively declaring the latest wave has already hit its peak.
According to Dr Waasila Jassat of South Africa's National Institute for Communicable Diseases, hospitals "never reached capacity".
The nation has a double-dosed vaccination rate of just 36 per cent but a high proportion of its citizens have already been infected.
South Africa saw a massive surge to almost 10,000 daily cases in early December, but the numbers have petered off at a rate of 20.8 per cent in the week leading into Christmas.
Francois Venter, a medical professor at the University of the Witwatersrand in Johannesburg, predicted that at the current rate of decline Omicron would "be pretty much gone" from all of South Africa by the end of January.
'Not a matter of if, but when'
Medical director for infection prevention at the Mount Sinai Health System, Dr Bernard Camins believes people have to come to terms with the fact they will be exposed to someone carrying the virus in the future.
"I've been telling this to anyone who would listen: It's not a matter of if you get exposed to the Omicron variant or any other variant of the coronavirus, it's a matter of when," he said.
"Everyone will run into somebody with a Covid infection," reported NBC.
However, Dr Otto Yang of the David Geffen School of Medicine at UCLA says just because you are exposed, it does not mean you will definitely contract the virus, regardless of the strain.
"I don't think it's a foregone conclusion that everybody will get Covid-19," he told the US Today Show.
"I would prefer not to learn to live with Covid. I would prefer to get rid of it, and theoretically, it's possible.
"The scenario that I'm hoping will play out is that the numbers of Covid cases are reduced drastically to the point that there are small outbreaks here and there that are easily contained and most of the population is not being exposed."
Yang encouraged the population to get their booster shots for the best possible protection against the Omicron strain.
"It's looking very much like people who get a booster have protection against getting it," he continued, adding there will "always be a possibility" for people to contract the virus regardless of vaccination status.
Director of the Centres for Disease Control and Prevention Dr Rochelle Walensky said "there are going to be breakthrough cases of Omicron, but they will be certainly milder if you're vaccinated and boosted.
"Certainly, your outcome is going to depend on your vaccination status. We will see that those who are vaccinated and boosted will have less severe outcomes, less risk of mortality."
Meanwhile, World Health Organisation Secretary General Tedros Adhanom Ghebreyesus has warned high-income countries should not prioritise booster shots while much of the world was not on track to be fully vaccinated by the end of 2022.
The Shot of Hope report, co-authored by an expert advisory group of researchers, analysts, and leaders from organisations including Melbourne's Burnet Institute, noted that some countries would not reach the 70 per cent double dose vaccination target until after 2030.
"The longer we allow developing countries to lag in terms of vaccination rates, the more time we give the virus to mutate and spread," End Covid For All spokesman Reverend Tim Costello said.
The report noted a survey of 77 epidemiologists from 28 countries found two-thirds believed it would take less than a year before Covid-19 mutated to the point where the majority of vaccines were rendered ineffective if authorities did not act fast enough.
"Speed is of the essence," the report stated.
"If we vaccinate the world faster, the likelihood of mutations drops. It is within our power to limit the chance of the next mutation from being so deadly and disruptive."
